A membrane electrode assembly (MEA) is generally located in the middle of a fuel cell stack and includes a polymer electrolyte membrane, through which hydrogen ions (protons) are transported, and an catalyst layer such as a cathode and an anode, in which an electrochemical reaction between hydrogen and oxygen takes place, disposed on each of both sides of the polymer electrolyte membrane.
A gas diffusion layer and a gasket are sequentially stacked on both sides of the MEA, where the cathode and the anode are located. A separator including flow fields for supplying fuel and discharging water generated by the reaction is located on the outside of the GDL, and an end plate for supporting and fixing the above-described components is connected to each of both ends thereof.
At the anode of the fuel cell stack, hydrogen is dissociated into hydrogen ions (protons, H+) and electrons (e−) by an oxidation reaction of hydrogen. The hydrogen ions and electrons are transmitted to the cathode through the electrolyte membrane and an external circuit respectively. At the cathode, water is produced by an electrochemical reaction in which the hydrogen ions and electrons transmitted from the anode and the oxygen in air participate and, at the same time, electrical energy is produced by the flow of electrons.
The gasket, which is disposed between the separator and the MEA, serves as a guide that moves the air and hydrogen to the anode and the cathode, and the gasket serves as a gas path that discharges a reaction gas generated in the catalyst layer.
Condensate is formed in the gas path through which the reaction gas or the air passes, and the condensate can block the gas path. Thus, performance of the fuel cell stack cannot be stably maintained, and can be decreased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.